• Applied Microscopy
• /
• v.26 no.4
• /
• pp.431-446
• /
• 1996

This experiment was performed to study the ultrastructural changes of the juxtaglomerular cell of mice following subcutaneous injection of heavy metallic agents. Male mice were divided into normal and experimental groups. The mice were subcutaneouly injected with $HgCl_2$ (2mg, 5mg or 10 mg/Kg/BW) or with $K_{2}Cr_{2}O_7$(5 mg, 10 mg or 20 mg/Kg/BW). Mice were sacrificed on 6 hours, 3 days and 14 days after the injection. Kidneys were fixed in the 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by refixation in the 1% osmium tetroxide solution. Dehydrated blocks were embedded in araldite mixture. The sections were cut on a LKB-V ultratome, and ultrathin sections stained with uranyl acetate and lead citrate were observed with JEM 100CX II electron microscope. The results were as follow: 1. Juxtaglomerular cell of the experimental groups showed some alterations, especially in the structures of protein synthesis including dilations and degradations of granular endoplasmic reticula, atrophy of Golgi complex, and numerous free ribosomes in the cytoplasm. 2. Juxtaglomerular cells treated groups showed a number of vacuoles, protogranules and some myelin figures in the cytoplasm, especially in the earlier groups. 3. Juxtaglomerular cells of treated groups, contained a large number of secretory granules showing variable electron densities and pleomorphism in later groups (2 weeks). From the above results, it was concluded that, the mercuric chloride or potassium bichromate induces acute renin release from juxtaglomerular cells of the mice, but many juxtaglomerular cells may secrete prematured secretory granules, or the synthetic system of the cell can not perform normal function.

• The Korean Journal of Zoology
• /
• v.35 no.3
• /
• pp.372-382
• /
• 1992

당뇨병유발제인 streptozotocin이 생쥐 신장 사구체곁세포의 미세구조에 어떠한 영향을 미치는 지를 알아보고자 일반계통인 ICR생쥐와 유전성 당뇨병계통인 KK생쥐에 streptozotocin을 투여하여 경시적으로 각 동물의 신장 사구체곁세포의 미세구조의 변화를 관찰하였다. Streptozotocin을 투여한 ICR생쥐의 사구체곁세포는 3일째부터 과립형질내세망의 미약한 팽창과 과립내에 대소 공포의 출현 및 용해소체가 간혹 관찰되었다. 그후 시간이 지남에 따라 더욱 심하여 특히 2주 및 4주에서는 과립형질내세망의 팽창, 사립체, 골지장치 및 리보소곤 등이 소수 출현하였는데 비해 대소 용해소체는 많이 관찰되었으며 심한 탈과립으로 인해 세포질내 과립의 면적이 현저히 감소되었다. 그러나 KK생쥐의 실험군에서는 전 실험군에 걸쳐 퇴행성변화가 적었으며 ICR 생쥐 실험군에 비해 그 영향이 훨씬 적었다. 이상의 결과를 종합하여 보면 정상 ICR생쥐에 streptozotocin을 투여하자 되면 ICR생쥐 사구체곁세포에서 과립의 유의한 감소 및 세포내 미세구조의 퇴행성변화가 뚜렷한데 비해 KK생쥐 실험군에서는 ICR생쥐 실험군에 비해 손상을 적게 받았는데 이는 KK생쥐가 갖고 있는 당뇨병에 대한 내성에 의해 영향을 적게 미치는 것이 아닌가 추측된다.

• The Korean Journal of Physiology
• /
• v.20 no.2
• /
• pp.236-248
• /
• 1986

Alterations of renin-angiotensin system have been suggested as one of the mechanisms increasing arterial blood pressure in experimental and clinical hypertension. But the exact nature of high blood pressure in the early and late phase of renal hypertension is still controversial. To clarify the nature of renin release in both unclipped and clipped kidney of two kidney one clip Goldblatt lypertensive rat, experiments have been done in kidney slices, which were obtained from the rats of 3 and 7 days of operation. Basal rate of renin release was suppressed in unclipped kidney slices compared to clipped kidney Norepinephrine increased renin release from unclipped kidney slices, but not from clipped kidney slices. Suppressions by angiotensin Il and arginine vasopressin of renin release were attenuated in the clipped kidney slices compared to unclipped and sham-operated kidney slices. Increases by verapamil and trifluoperazine of renin release were attenuated in the clipped kidney slices compared to unclipped and sham-operated kidney slices. These results suggest that the negative feedback control mechanism of the renin-angiotensin system by angiotensin Il and arginine vasopressin is attenuated in the clipped kidney of two kidney one clip Goldblatt hypertensive rat, and that one of the altered mechanisms may be caused by certain regulatory changes of intracellular calcium and/or calcium-calmodulin complex in the juxtaglomerular cells.

• The Korean Journal of Physiology
• /
• v.25 no.1
• /
• pp.61-67
• /
• 1991

In order to determine possible relationships between the renin-angiotensin system and nephron heterogeneity, we compared the response of renin release and the angiotensin-converting enzyme (ACE) activity from different areas of the rat kidney. We used the renal cortical slices from the capsular surface to the juxtamedullary junction. Slices from outer one-third of the cortex were designated as outer cortical slices (OC), middle one-third as midcortical slices (MC), and inner one-third as inner cortical slices (IC). The renal renin content markedly decreased from OC and MC to IC. The basal lenin release was higher in OC than in MC or IC. On the contrary the percent change of renin release in response to L-isoproterenol was significantly higher in MC than in OC or IC. By TMB-8, the renin release in MC by $231{\pm}21%$ was higher than OC by $171{\pm}19%$ or IC by $$162{\pm}19. Angiotensin II suppressed renin release in OC and MC by $68{\pm}2,\;71{\pm}4%$ respectively, but only $40{\pm}7%$ in IC. The ACE activity was higher in IC than in OC, MC, medulla and papilla. The present data indicate that renin content and basal lenin release gradulally decreased from outer (OC) to inner (IC) cortex. The renin release in response to beta-adrenergic agonist, L-isoproterenol and intracellular calcium antagonist, TMB-8 were higher in MC than in OC and IC, but angiotensin II suppressed renin release less in IC than in OC and MC. It is suggested that juxtaglomerular cells of outer, mid-and inner cortices show a difference in renin release response to the stimuli.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.22 no.1
• /
• pp.84-89
• /
• 2018

Purpose Renin is a proteolytic enzyme synthesized and secreted from epidermal(juxtaglomerular) cells in kidney. Renin acts on the renin substrate angiotensinogen to produce angiotensin I, and then angiotensin II is produced by the action of angiotensin converting enzyme. This causes the adrenal glands to boost blood pressure (vasoconstriction) and promote aldosterone secretion. While Plasma renin activity (PRA) is to test angiotensin I, the active renin concentration (ARC) is a renin test directly. They have different test methods and their own substrates. However, these two methods are sometimes interpreted as the same as a result. The purpose of this study was to evaluate the usefulness of the ARC test by comparing the results between PRA and ARC. Materials and Methods For the diversity of the experiment, 26 samples were requested to test with PRA(TFB company) and ARC(Cisbio company) to other institution. We compared and analyzed PRA(Immunotech company) and ARC(Cisbio company) tests using 28 samples from September $15^{th}$ to October $13^{th}$ in 2017. The statistical analysis method for PRA/ARC evaluated the usefulness using Microsoft Excel program by verifying a correlation analysis of Aldosterone/PRA ratio and a correlation analysis of Aldosterone/ARC ratio and conducting T-test. Results The regression equation of the PRA(Immunotech company)/ARC(Cisbio company), which was tested in the department, was y = 0.0619x + 0.4615 and the correlation coefficient was 0.73. The regression equation of the PRA(TFB company)/ARC(Cisbio company), which was tested in the other institution, was y = 0.0888x + 0.3316 and the correlation coefficient was 0.91. In addition, The regression equation of Aldosterone / PRA ratio and Aldosterone / ARC ratio was y = 0.875x - 11.688 and the correlation coefficient was 0.87. Plus T - test showed no significant difference (P>0.05). Conclusion Both tests showed a strong positive correlation, but this only represents the strength and direction of the relationship between the two tests. Furthermore, the actual results showed somewhat differences. It is presumed that the measured value was influenced by the endogenous renin group mass in the plasma, the condition of the enzyme reaction and the kind of the inhibitor. When the active renin concentration (ARC) test is performed, it is useful to distinguish between the two tests as they are complementary.

• Applied Microscopy
• /
• v.34 no.4
• /
• pp.241-254
• /
• 2004

Kidney had recovery functions against toxicants, ischemia, reperfusion-induced damage, acute-renal failure (ARF). Urinary epidermal growth factor (EGF) is produced by the juxtaglomerular apparatus. Kidney accumulates or excretes the EGF. In case of renal diseases, excreted EGF was decreased. The aim of this study is to evaluate the effects squalene (SQ) on the prevention of experimental acute renal failure induced by glycerol. In case of in vitro study, we investigated the expression of EGF by RT-PCR. After the proximal tubular cells was isolated, glycerol (1, 2, 4 mM) or glycerol plus squalene (0.1, 0.05 or 0.1%) was added. In case of in vivo study, we investigated the changes of BUN, creatine, and ultrastructure. Experimental groups were divided into four groups. Group 1 was normal mouse. Group 2 was injected with SQ only (180 mg/kg). Group 3 was not treated with squalene after intraperitoneal contamination of glycerol (50%, 8 ml/kg). And, Group 4 was treated with squalene (180 mg/kg) after intraperitoneal contamination of glycerol (50%, 8 ml/kg). All groups were used to 7 mice. In the results, we investigated the glycerol induced renal failure. The expression of EGF mRNA was decreased in renal proximal tubules when treated with only glycerol. SQ increased the mRNA expression of EGF in renal proximal tubules. SQ also quickly recovered the levels of BUN and creatine compared with those of mice treated with only glycerol (P<0.01). In case of ultrastructure, group 3 had heavily damaged mitochondria, but, mitochondria in group 4 had evidences of the recovery. It was concluded that SQ had the recovery effects for the glycerol-induced acute renal failure.